WASHINGTON, March 3 (Reuters) - The House Judiciary Committee will seek documents from more than 60 people and organizations as it begins investigations into possible obstruction of justice and abuse of power by President Donald Trump, the panel's chairman said on Sunday.

"We are going to initiate investigations into abuses of power, into corruption ... and into obstruction of justice," Nadler said. "It's our job to protect the rule of law."

"It's very clear that the president obstructed justice," Nadler said. He said it was too soon to consider whether impeachment should be pursued, however.

"Before you impeach somebody, you have to persuade the American public that it ought to happen," he said.

As evidence of obstruction, Nadler cited Trump's May 2017 firing of FBI Director James Comey, who was leading an investigation into Russia activities in the 2016 U.S. presidential election and possible collusion with Trump's campaign.

That investigation was subsequently taken over by Special Counsel Robert Mueller, who is expected to deliver his findings to the U.S. attorney general within weeks.

To aid its inquiry into possible obstruction of justice, the committee is expected to focus its document requests on actions by Trump that could constitute efforts to remove perceived enemies and install more loyal replacements at the Justice Department, according to a person familiar with the matter.

On "This Week", Nadler also cited what he called Trump's attempts to intimidate witnesses in the investigation. The source said that, as part of its investigations into possible abuses of power, the committee would examine both potential promises of pardons as well as witness tampering and Trump's attacks on investigations and the press.

Nadler said that on Monday the committee will release the list of people and organizations it would request documents from.

Trump has denied his campaign worked with Moscow. "I am an innocent man being persecuted by some very bad, conflicted & corrupt people in a Witch Hunt that is illegal & should never have been allowed to start," Trump said in a tweet on Sunday.

The White House and the Trump Organization did not respond to requests for comment on Nadler's remarks.

Trump told a group of conservative activists and politicians on Saturday that investigators want to look at his finances and business dealings because no evidence of collusion has been found. "All of a sudden they are trying to take you out with bullshit," he said.

While the Mueller investigation is focused on specific crimes, Congress' probes will cast a wider net, Nadler said.

Congressional investigators will also look at whether Trump used the White House for personal enrichment in violation of the Constitution's emoluments clause, he said.

"This investigation goes far beyond collusion," said Nadler, whose committee would take the lead in any effort to impeach the president.

House Republican leader Kevin McCarthy attacked Nadler as having an impeachment agenda.

"They're setting a whole new course because there's no collusion so they want to build something else," he told ABC.

Several U.S. congressional committees are pursuing investigations focusing on Trump.

The House Intelligence Committee's Democratic chairman, Adam Schiff, said his panel would look at negotiations to build a Trump Tower in Moscow, which Cohen said continued well into the 2016 presidential campaign.

"That was a deal that stood to make him more money than any other deal in his life and it was a deal where he was pursuing help from the Kremlin, from (Russian President Vladimir) Putin himself, at a time when Putin was seeking relief from sanctions," Schiff told CBS' "Face the Nation."

"That is the most compromising circumstance that I can imagine." (Reporting by Tim Ahmann, Doina Chiacu and David Morgan; Editing by Sonya Hepinstall and Daniel Wallis)

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